Jump Ring Calculator

Calculate jump ring dimensions, aspect ratios, and total wire needed for a batch. See which chainmaille weaves your rings will work with.

The outer diameter of your mandrel or dowel.

Auto-fills wire diameter below.

Or enter directly to override gauge.

Leave empty to calculate a single ring only.

Extra wire for saw kerf and mistakes.

Inner Diameter

4.00mm


Outer Diameter

6.05mm

Aspect Ratio

3.91AR

Rings per Inch of Mandrel

24.8rings/in

Wire per Ring

15.78mm

Total Wire

1736.2mm

Total Wire (feet)

5.70ft

Aspect Ratio Reference

Highlighted row matches your current AR (3.91).

AR RangeCompatible Weaves
2.5 – 31-in-1 chain
3 – 3.5Byzantine, Box chain
3.5 – 4Full Persian, Jens Pind
4 – 5European 4-in-1, Dragonscale
5+Japanese patterns, Loose weaves

Tips

  • Rings spring back slightly after cutting — actual ID may be 0.1-0.2mm larger than mandrel size.
  • For consistent rings, wind your coil tightly and use a jeweler's saw (not flush cutters) for clean ends.
  • Aspect ratio is the most important number for chainmaille — it determines which weaves will work.

How It Works

The key number for chainmaille is the aspect ratio (AR) — the ring's inner diameter divided by the wire diameter. This single number determines which weaves will work with your rings. Too low and the rings won't fit through each other; too high and the weave will be loose and floppy. The calculator gives you the AR from your mandrel size and wire gauge so you can check weave compatibility before winding and cutting a whole batch.

Wire per ring is the circumference measured at the middle of the wire: π × (inner diameter + wire diameter).

Have an idea or found a bug? Let me know — I read every message.